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CROSSFIRE TO CARB.

 
docwilcar
I love my Chevy Chevette!
Posts: 1
Joined: 05/11
Posted: 12/01/11 07:33 AM

I have an 84 Z51 with 68K that I just converted to carb. I wanted some additional performance and did not want to modify the crossfire system.  I used a ZZ4 intake and 600 edelbrock carb, an accel HEI distributor, Mallory fuel regulator with return line and a Crane 274H06 218-218 .450 lift 106 LSA camshaft. For the fuel system I ran a 12 GA. wire from a relay mounted near the battery all the way back to the fuel pump power wire(original power wire through oil pressure switch not used). I powered the relay with a 10 GA. wire from the positive post on the alternator through a circuit breaker(can use a regular fuse instead)to the relay.  I used 12 volt switched power to trigger the relay.  The fuel pump now turns on when the key is turned on and there is no oil pressure switch function.  I also wired in a Ford inertia switch so that in a crash the fuel pump will turn off.  I have a 2" air cleaner that is very close when I shut the hood but it does work okay but a high rise intake would probably not close.  Engine has much better performance and easier tuning, at least for me!  I had most of the conversion parts in inventory(had a 76 L82) and did all the work myself so it did not cost me much.  I also eliminated my smog pump and ac compressor to clean up the engine bay.   If you have questions please feel free to contact me at  docwilcar@yahoo.com  

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Jeremy Delvalle
I love my Chevy Chevette!
Posts: 5
Joined: 10/13
Posted: 10/24/13 05:48 AM

Can you put a 670 Holley carb on a stock c4 motor or do I have to change some stuff any help?  

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Jeremy Delvalle
I love my Chevy Chevette!
Posts: 5
Joined: 10/13
Posted: 10/24/13 05:51 AM

Got the car already with a carb but only lets me put five dollars of gas no more?any part I'm missing  

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Jeremy Delvalle
I love my Chevy Chevette!
Posts: 5
Joined: 10/13
Posted: 10/24/13 09:05 AM

Need help got a 84 corvette swapped out the cross fire and they changed it to a carb.can I put a 670 Holley on there.your do I have to change cam and other parts.cant fill up the tank just let's me put in five bucks I don't know what is the problem any help thank you  

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wayne712222
My first time was in a Chevy
Posts: 140
Joined: 10/13
Posted: 10/24/13 10:28 PM

you can leave the L83 cam.. it will work ..


i had not gone thru this thread.. as i understand how to swap carbs onto these..

but i also understand how to make the crossfire fuel injection systems work...

so.. yes... you can use ANY carb...

you will need a vacuum advance type HEI distributor...
as the crossfire has full electronic spark timing..

hopefully you did not chop and cut a bunch of things..

you can pull the sending unit and replace the pump with a 6 pound in tank fuel pump from an 87 chevy truck with a carb to eliminate the need to have a fuel pressure regulator .

you can get fittings to convert the oring fuel fittings to SAE flair...

there are short sections available also.. so you can connect at one of the splices somewhere in the system and convert the forward part of the fuel lines away from Oring.. to inverted flair...

AND A MONSTER of a warning..

ON 84 CROSS FIRES... the COMPUTER DOES NOT command the electric radiator cooling fan on...

ONLY 2 things command that.. the high pressure switch on the high pressure tubing out the back of the ac compressor... and the radiator fan switch on the RIGHT HAND cylinder head. between the 6 and 8 spark plugs..

the 85 and UP L98 TPI motors have these swapped into the drivers side cylinder head...


you will probably  be just as good off with a return type fuel pressure regulator ...


what's going to happen with the removed fuel injection parts???? Ebay?? or keep them ???  

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Jeremy Delvalle
I love my Chevy Chevette!
Posts: 5
Joined: 10/13
Posted: 10/30/13 04:19 AM

I got corvette already with the carb.I think its bad because when I crank it up it dose a grinding sound like if the stater is bad or the carb is bad not sending me gas to the motor then it will fire up.aother thing is when the motor is cold sometimes it will just turn off  

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Jeremy Delvalle
I love my Chevy Chevette!
Posts: 5
Joined: 10/13
Posted: 10/30/13 04:19 AM

I got corvette already with the carb.I think its bad because when I crank it up it dose a grinding sound like if the stater is bad or the carb is bad not sending me gas to the motor then it will fire up.aother thing is when the motor is cold sometimes it will just turn off  

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wayne712222
My first time was in a Chevy
Posts: 140
Joined: 10/13
Posted: 10/30/13 07:52 AM

Jeremy lets look at the problems one at a time...


when I crank it up it dose a grinding sound like if the stater is bad

is the starter grinding???  can you do me a favor..  get the block numbers from the top of the back of the block behind the heads.. visible with a flashlight.  there will be big numbers in one side.. and a julian date..also.. perhaps on the other side.. a julian date looks like it has flat head screws on either end..(\)B144(/)  that would indicate feb 14 1984  there is also a block stamping numbers on the top of the deck surface in front of the passenger side cylinder head..  there are 2 rows of numbers. one larger than the other.. copy both.. post them and the casting number..

why am i having you go thru this 5 minutes of work..

your engine oil dipstick should be on the right side of the block..at the end of the 1981 model year.. the blocks went to SOME METRIC holes.. usually just the starter holes... so 1982 and up blocks except for GMPP blocks are drilled for metric screws...

if the bolts are SAE... and the starter drilled for metric.. like it should be.. it will wiggle around.. and make grinding noises like you describe..

please check the heads of the starter bolts.. if there are numbers like 10.9 on them.. they are metric.. if there are 3 or 6 stripes. they are SAE..

there are ways to tell what block you have.. by the numbers cast into it and stamped in..

if you pull the torque converter cover... you can take a piece of 1/8" wire.. or drill.. and stick it between the outside of the ring gear and the bare shaft on the starter.. if its won't fit in.. the starter needs to be shimmed.. if it wobbles when its in there. you need to remove shims...



thats how we get the starter in proper alignment.

you can loosen the bolts 3/4 turn.. and see if the starter wobbles on the bolts.. this usually happens with SAE bolts and a metric starter..

warning.. DO NOT ATTEMPT TO INSTALL METRIC BOLTS if they don't thread in almost all the way by hand.. you will SPLIT the block and ruin it..  

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wayne712222
My first time was in a Chevy
Posts: 140
Joined: 10/13
Posted: 10/30/13 08:12 AM

continued..


or the carb is bad not sending me gas to the motor then it will fire up.

does it take a while to fire up when cold.. that could be several things...


another thing is when the motor is cold sometimes it will just turn off  


since the fuel injection was removed from your car..

you have to treat it like a old style with a carb...

you need to depress the throttle part way before cranking.. to release the fast idle cam on the choke so the choke snaps closed.. and the fast idle cam holds the throttle part way open..

if this does not fix the issue of cold starts..


we will have to get into choke and fast idle adjustments...

there is one additional issue..

how is the fuel supplied to the carb.. did they use the existing in tank electric fuel pump... or did they convert to a mechanical fuel pump????

if you are still running an electric fuel pump.. i have some changes you might need to perform to make it carb friendly.

why... in a fuel injected system.. the key comes on  and the computer cycles on the electric fuel pump for 2 seconds to bring up the fuel pressure.. so it will be at pressure as soon as you start to crank..  without the ECM to turn the fuel pump relay on for the 2 second prime and then again while cranking and hold it in the run position once the engine is running.. you might be having an issue like that..

there is a 2 prong oil pressure switch that is in parallel with the fuel pump relay.. so either one can power up the fuel pump circuit..

this will turn on the fuel pump when the engine is being cranked and while running when the oil pressure is above 3 PSI...  or 5 psi.... so it will usually handle missing the ECM controlling the fuel pump relay...  

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Christopher W Sampsel
I love my Chevy Chevette!
Posts: 1
Joined: 05/14
Posted: 05/06/14 02:44 PM

I seen your post on the web about putting a carb motor in a 84 corvette I have recently bought a 84 corvette with a bad motor and a bad crossfire system I bought a new 383 crate motor and carb and fuel regulator with return and new headers and stall tork the transmission has a shift kit in it and also a new after market cluster is there anything else I need to replace thank you chris  

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wayne712222
My first time was in a Chevy
Posts: 140
Joined: 10/13
Posted: 05/07/14 05:08 AM

hmm... the exact article on swapping a carb onto a 84 C4 corvette..

http://www.hotrod.com/techarticles/1403_engine_swap_corvette_350ci/  

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